Cytochemical localization of 5'-nucleotidase activity in the nodose ganglion of the rabbit.

5'-nucleotidase (5'N) activity was histochemically examined in the rabbit nodose ganglion at light and electron microscopic levels. Under the light microscope, the 5'N activity was clearly demonstrated on the satellite cells and their processes surrounding neurons. No deposits of reaction product were observed within the perikarya of the ganglion cells and at intracellular sites in the glial cells. Electron microscopically, the reaction product of enzyme activity was located in both neuronal and satellite cell membranes, usually on the external surface. The glial cells exhibit the enzyme activity more extensively than the neurons. The presence of membrane-bound 5'N activity on the external aspect of the plasma membranes supports earlier findings that the functional role of the enzyme in the primary sensory neurons is related to processes of intracellular communication.